Bicycle frame



FIG. 1 is a right front perspective view of a bicycle frame, showing my new design, wherein the bicycle portions shown in broken lines are for illustrative purposes only and form no part of the claimed invention;

FIG. 2 is a right elevational view thereof, the left elevational view being a mirror image thereof;

FIG. 3 is front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a bicycle frame, as shown and described. 